/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at
http://mozilla.org/MPL/2.0/. */
import { clearTimeout, setTimeout } from "resource://gre/modules/Timer.sys.mjs";
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
});
const ARGUMENTS = "__webDriverArguments";
const CALLBACK = "__webDriverCallback";
const COMPLETE = "__webDriverComplete";
const DEFAULT_TIMEOUT = 10000; // ms
const FINISH = "finish";
/** @namespace */
export const evaluate = {};
/**
* Evaluate a script in given sandbox.
*
* The the provided `script` will be wrapped in an anonymous function
* with the `args` argument applied.
*
* The arguments provided by the `args<` argument are exposed
* through the `arguments` object available in the script context,
* and if the script is executed asynchronously with the `async`
* option, an additional last argument that is synonymous to the
* name `resolve` is appended, and can be accessed
* through `arguments[arguments.length - 1]`.
*
* The `timeout` option specifies the duration for how long the
* script should be allowed to run before it is interrupted and aborted.
* An interrupted script will cause a {@link ScriptTimeoutError} to occur.
*
* The `async` option indicates that the script will not return
* until the `resolve` callback is invoked,
* which is analogous to the last argument of the `arguments` object.
*
* The `file` option is used in error messages to provide information
* on the origin script file in the local end.
*
* The `line` option is used in error messages, along with `filename`,
* to provide the line number in the origin script file on the local end.
*
* @param {nsISandbox} sb
* Sandbox the script will be evaluted in.
* @param {string} script
* Script to evaluate.
* @param {Array.<?>=} args
* A sequence of arguments to call the script with.
* @param {object=} options
* @param {boolean=} options.async
* Indicates if the script should return immediately or wait for
* the callback to be invoked before returning. Defaults to false.
* @param {string=} options.file
* File location of the program in the client. Defaults to "dummy file".
* @param {number=} options.line
* Line number of the program in the client. Defaults to 0.
* @param {number=} options.timeout
* Duration in milliseconds before interrupting the script. Defaults to
* DEFAULT_TIMEOUT.
*
* @returns {Promise}
* A promise that when resolved will give you the return value from
* the script. Note that the return value requires serialisation before
* it can be sent to the client.
*
* @throws {JavaScriptError}
* If an {@link Error} was thrown whilst evaluating the script.
* @throws {ScriptTimeoutError}
* If the script was interrupted due to script timeout.
*/
evaluate.sandbox = function (
sb,
script,
args = [],
{
async = false,
file = "dummy file",
line = 0,
timeout = DEFAULT_TIMEOUT,
} = {}
) {
let unloadHandler;
let marionetteSandbox = sandbox.create(sb.window);
// timeout handler
let scriptTimeoutID, timeoutPromise;
if (timeout !== null) {
timeoutPromise = new Promise((resolve, reject) => {
scriptTimeoutID = setTimeout(() => {
reject(
new lazy.error.ScriptTimeoutError(`Timed out after ${timeout} ms`)
);
}, timeout);
});
}
let promise = new Promise((resolve, reject) => {
let src = "";
sb[COMPLETE] = resolve;
sb[ARGUMENTS] = sandbox.cloneInto(args, sb);
// callback function made private
// so that introspection is possible
// on the arguments object
if (async) {
sb[CALLBACK] = sb[COMPLETE];
src += `${ARGUMENTS}.push(rv => ${CALLBACK}(rv));`;
}
src += `(function() {
${script}
}).apply(null, ${ARGUMENTS})`;
unloadHandler = sandbox.cloneInto(
() => reject(new lazy.error.JavaScriptError("Document was unloaded")),
marionetteSandbox
);
marionetteSandbox.window.addEventListener("unload", unloadHandler);
let promises = [
Cu.evalInSandbox(
src,
sb,
"1.8",
file,
line,
/* enforceFilenameRestrictions */ false
),
timeoutPromise,
];
// Wait for the immediate result of calling evalInSandbox, or a timeout.
// Only resolve the promise if the scriptPromise was resolved and is not
// async, because the latter has to call resolve() itself.
Promise.race(promises).then(
value => {
if (!async) {
resolve(value);
}
},
err => {
reject(err);
}
);
});
// This block is mainly for async scripts, which escape the inner promise
// when calling resolve() on their own. The timeout promise will be re-used
// to break out after the initially setup timeout.
return Promise.race([promise, timeoutPromise])
.catch(err => {
// Only raise valid errors for both the sync and async scripts.
if (err instanceof lazy.error.ScriptTimeoutError) {
throw err;
}
throw new lazy.error.JavaScriptError(err);
})
.finally(() => {
clearTimeout(scriptTimeoutID);
marionetteSandbox.window.removeEventListener("unload", unloadHandler);
});
};
/**
* `Cu.isDeadWrapper` does not return true for a dead sandbox that
* was assosciated with and extension popup. This provides a way to
* still test for a dead object.
*
* @param {object} obj
* A potentially dead object.
* @param {string} prop
* Name of a property on the object.
*
* @returns {boolean}
* True if <var>obj</var> is dead, false otherwise.
*/
evaluate.isDead = function (obj, prop) {
try {
obj[prop];
} catch (e) {
if (e.message.includes("dead object")) {
return true;
}
throw e;
}
return false;
};
export const sandbox = {};
/**
* Provides a safe way to take an object defined in a privileged scope and
* create a structured clone of it in a less-privileged scope. It returns
* a reference to the clone.
*
* Unlike for {@link Components.utils.cloneInto}, `obj` may contain
* functions and DOM elements.
*/
sandbox.cloneInto = function (obj, sb) {
return Cu.cloneInto(obj, sb, { cloneFunctions: true, wrapReflectors: true });
};
/**
* Augment given sandbox by an adapter that has an `exports` map
* property, or a normal map, of function names and function references.
*
* @param {Sandbox} sb
* The sandbox to augment.
* @param {object} adapter
* Object that holds an `exports` property, or a map, of function
* names and function references.
*
* @returns {Sandbox}
* The augmented sandbox.
*/
sandbox.augment = function (sb, adapter) {
function* entries(obj) {
for (let key of Object.keys(obj)) {
yield [key, obj[key]];
}
}
let funcs = adapter.exports || entries(adapter);
for (let [name, func] of funcs) {
sb[name] = func;
}
return sb;
};
/**
* Creates a sandbox.
*
* @param {Window} win
* The DOM Window object.
* @param {nsIPrincipal=} principal
* An optional, custom principal to prefer over the Window. Useful if
* you need elevated security permissions.
*
* @returns {Sandbox}
* The created sandbox.
*/
sandbox.create = function (win, principal = null, opts = {}) {
let p = principal || win;
opts = Object.assign(
{
sameZoneAs: win,
sandboxPrototype: win,
wantComponents: true,
wantXrays: true,
wantGlobalProperties: ["ChromeUtils"],
},
opts
);
return new Cu.Sandbox(p, opts);
};
/**
* Creates a mutable sandbox, where changes to the global scope
* will have lasting side-effects.
*
* @param {Window} win
* The DOM Window object.
*
* @returns {Sandbox}
* The created sandbox.
*/
sandbox.createMutable = function (win) {
let opts = {
wantComponents: false,
wantXrays: false,
};
// Note: We waive Xrays here to match potentially-accidental old behavior.
return Cu.waiveXrays(sandbox.create(win, null, opts));
};
sandbox.createSystemPrincipal = function (win) {
let principal = Cc["@mozilla.org/systemprincipal;1"].createInstance(
Ci.nsIPrincipal
);
return sandbox.create(win, principal);
};
sandbox.createSimpleTest = function (win, harness) {
let sb = sandbox.create(win);
sb = sandbox.augment(sb, harness);
sb[FINISH] = () => sb[COMPLETE](harness.generate_results());
return sb;
};
/**
* Sandbox storage. When the user requests a sandbox by a specific name,
* if one exists in the storage this will be used as long as its window
* reference is still valid.
*
* @memberof evaluate
*/
export class Sandboxes {
/**
* @param {function(): Window} windowFn
* A function that returns the references to the current Window
* object.
*/
constructor(windowFn) {
this.windowFn_ = windowFn;
this.boxes_ = new Map();
}
get window_() {
return this.windowFn_();
}
/**
* Factory function for getting a sandbox by name, or failing that,
* creating a new one.
*
* If the sandbox' window does not match the provided window, a new one
* will be created.
*
* @param {string} name
* The name of the sandbox to get or create.
* @param {boolean=} [fresh=false] fresh
* Remove old sandbox by name first, if it exists.
*
* @returns {Sandbox}
* A used or fresh sandbox.
*/
get(name = "default", fresh = false) {
let sb = this.boxes_.get(name);
if (sb) {
if (fresh || evaluate.isDead(sb, "window") || sb.window != this.window_) {
this.boxes_.delete(name);
return this.get(name, false);
}
} else {
if (name == "system") {
sb = sandbox.createSystemPrincipal(this.window_);
} else {
sb = sandbox.create(this.window_);
}
this.boxes_.set(name, sb);
}
return sb;
}
/** Clears cache of sandboxes. */
clear() {
this.boxes_.clear();
}
}
